A semiconductor manufacturing process includes a process of performing a processing using plasma. In the processing process using plasma, the uniformity of the plasma generated in a processing apparatus is one of important factors that determine the properties of a semiconductor to be manufactured. Therefore, the processing process using plasma is required to control the distribution of plasma with high precision. In order to reduce the bias of plasma generated in the processing apparatus, a plasma generating space in the processing apparatus may be made to have a symmetrical structure. However, in many cases, even if the plasma generating space is designed to have a symmetrical structure, the space within the processing apparatus is not formed to have a symmetrical structure due to, for example, errors in the processing dimensions of components, variations in assembly, or consumption of components.
To avoid this, a technique has been known in which an electrode for generating plasma is divided into a central portion and a peripheral portion, and the impedance between the central portion and a ground and the impedance between the peripheral portion and the ground are controlled so as to control the distribution of plasma in a diametric direction. In addition, a technique has been known in which a device that controls the impedance between a power supply unit and a ground is provided around the power supply unit that applies high frequency power to an electrode, and the distribution of high frequency power applied to the electrode is controlled in a peripheral direction. See, for example, U.S. Pat. No. 8,299,390, Japanese Patent Laid-open Publication No. 2009-164608, and U.S. Pat. No. 8,652,297.